Damper



United States Patent O DAMPER Lester W. Ericson, Minneapolis, Minn., assignor to Tri- Bilt Products Inc., Minneapolis, Minn., a corporation of Minnesota Application December 7, 1951, Serial No. 260,375

8 Claims. (Cl. 126-285) The herein disclosed invention relates to dampers and has for an object to provide a damper consisting of two sheets of sheet material overlying one another and disposed in spaced relation to form an air space therebetween for cooling the damper.

Another object of the invention resides in providing a frame having an opening therein adapted to be closed by the damper and in further providing a shaft together with bearings carried by the frame and supporting the shaft for swinging movement.

An object of the invention resides in disposing said sheets, one on each side of the said shaft and in attaching the sheets to the shaft.

A still further object of the invention resides in providing means for causing a circulation of air through the space between the sheets to cool the damper.

An object of the invention resides in constructing the inner sheet of lesser width than the outer sheet to form passageways communicating with the space between the sheets and the interior and in further providing openings inthe outer sheet communicating with said space and with the exterior.

A feature of the invention resides in providing closure means for engagement .with the marginal portions of said damper for closing said opening through the frame and lin constructing the damper flexible at the marginal portions of the same to cause the damper to closely overlie the closure means throughout the extent thereof.

A11 object of the invention resides in constructing certain of the sheets with channels having grooves facing the shaft and in further constructing the adjoining sheets with marginal portions received in said grooves and slidable therein to accommodate twisting and bending of the sheets to conform to the surfaces of the closure means engaged thereby.

A still further object of the invention `resides in constructing said channels by forming flanges on certain of the longitudinal portions of the sheets, said flanges being bent back upon the sheets and spaced therefrom `to form inwardly facing grooves in which the marginal portions of the 'adjoining sheets are received.

Other objects of the invention reside in the novel combination and arrangement of parts and in the details of construction hereinafter illustrated and/ or described.

in the drawings:

Fig. l is an elevational view of aframe having two openings therein and provided with 'a series of dampers embodying the invention for closing said openings.

Fig. 2 is an `elevational sectional view taken on line 2--2 of Fig. 1 and drawn to a greater scale.

Fig. 3 is a cross sectional view taken on line 3-3 of Fig. 2 `and drawn to a still greater scale.

Fig. 4 is an elevational view of a portion of the structure shown in Fig. 2 illustrating the parts in altered position and drawn `to the same scale as Fig. 2.

Fig. 5 is a plan view of one of .the dampers shown in Fig. 1 removed from the frame and drawn to 1a greater scale Vthan Fig. l.

2,718,885 Patented Sept. 27, 1955 ICC Fig. 6 is an end view of the structure shown in Fig. 5 and drawn to the same scale.

In the drawings have been shown a frame having vertical frame members and cross frame members connected thereto and forming two openings in the frame. On the vertical frame members are bearings which rotatably support a series of horizontally disposed shafts each supporting a damper of similar construction. The shafts have arms connected to the same which have connected to the ends thereof interconnected vertically extending aligned links whereby the shafts may be simultaneously rotated in their bearings and the dampers moved from closing .to opening position and vice versa. An electric motor provided with reduction gearing drives a crank having a pitman connected thereto and to one of said links. Each of the dampers consists of two sheets of sheet material which are attached to the shaft intermediate the longitudinal portions of said sheets. Each of said sheets has a flange bent outwardly therefrom and in spaced relation to the longitudinal portion of the sheet from which it issues Vto form a channel having a groove therein facing the shaft on which the damper is mounted. The opposite sheets rave marginal portions received in said grooves .and slidable therein to permit weaving of the sheets. The marginal portions of certain of the dampers are adapted to engage closure means on the frame while the marginal portions of other of the dampers are adapted to engage 4the corresponding portions of adjoining dampers to affect closure of the opening in the frame. The inner sheets of each damper are formed shorter than the outer sheets to provide a passageway communicating with the space between the sheets and the interior and the outer sheets are formed with openings communicating with said space and the exterior whereby air may circulate through the Aspace between the sheets and cool the damper.

In Fig. l a frame 10 has been shown which consists of vertical frame members 11, 12 and 13 and horizontal frame members 14 and 15 at the upper and lower ends of the vertical frame members. The frame members 11, 12, 14 and 15 consist of channel members 16 shown in detail in Fig. 2 which are welded together at the corners. Overlying the channel members are angle members 17 which have flanges 18 and 19. ri`he flanges 18 rest upon the flanges 20 of the channel members 16 `and are secured thereto by means of bolts, rivets or welding as may be desired. Such construction being well-known in the art has not been shown in the drawings. The anges 18 of said angles have secured to them at their corners corner plates 21 which are welded to said flanges. The frame member 13 consists of two plates 22 which are arranged in spaced relation and which have disposed between them a `channel member 23 which is welded to said plates. These plates are of the same width as the combined width of the channel members 16 and the angle members 17. The channel member 23 has anges 24 which overlie the plates 22 .and a web 25 disposed therebetween. By means of the construction shown two openings 26 .and 27 are formed in the frame 10.

The openings 26 and 27 are closed by means of a number of dampers 2S which are identical in constructionand which dampers cooperate with one `another and the frame ,and close the openings therethrough permitting the pas .sage of air through the same. Since `all of said dampers and the structure for supporting the same are identical, only one damper will be described in detail.

The damper 28 shown in Fig. 5 includes a shaft 29. This shaft is disposed in notches 30 formed in the ange 19 of angle member 17 and in one of the plates 22. The said shaft is journaled in a bearing 131 attached to the flange 18 of angle ymember 17 by means of lbolts 32 and in another bearing 33, best shown in Fig. 2, and

v 3 attached to the web of channel 23 by means of bolts 34.

The damper 28 further comprises two sheets 35 and 36 of flexible resilient sheet material preferably of metal which overlie one another and which are disposed one on each side of the shaft 29. These sheets are attached to the shaft by means of rivets 37 which extend through said sheets and shaft and are headed over as best shown in Fig. 6. The sheet is the outermost sheet of the damper while the sheet 36 is the innermost sheet. The sheet 35 has a longitudinal edge 38 with a marginal portion 39 following along said edge, both being disposed on one side of the shaft 29. The sheet 36 similarly has `a longitudinal edge 40 and a marginal portion 41 following along said edge and both disposed on the opposite side of the shaft 29. Sheet 35 has a longitudinal portion 42 which follows along the longitudinal edge 40 of sheet 36 and which has a flange 43 turned inwardly therefrom and spaced from the longitudinal portion 42 to form therewith a channel 44 having a groove 45 facing the shaft 29. In a similar manner sheet 36 has a longitudinal portion 46 formed with a flange 47 bent outwardly therefrom and spaced from said longitudinal portion to form a channel 48 having a groove 49 therein, said groove facing the shaft 29. The marginal portions 39 and 41 and the longitudinal portions 42 and 46 constitute the terminal portions of the sheets 35 and 36. As best shown in Figs. 5 and 6 the marginal portion 41 of sheet 36 is received in groove while the marginal portion 39 of sheet 35 is received in the groove 49. These grooves are of sufficient width so that the marginal portions of the sheets may slide in the same. By means of this construction the sheets may twist and bend relative to one another whereby the longitudinal portions of the sheets may be shifted out of the common plane of the damper.

The dampers are of such width that the longitudinal portions 42 and 46 of adjoining dampers overlie each other when the dampers are closed. Such portions of one damper forms closure means for engagement with the companion damper to block the passage of air through the same. For the upper and lower dampers, bars 50 are provided which are secured to the flanges 19 of angle members 17 of the frame members 14 and 15 and which serve the same purpose as the closure members formed by the marginal portions of the damper themselves.

It will be noted in Fig 5 that the inner sheet 36 is shorter than the outer sheet 35. The outer sheet tits closely between the plates 22 and the flanges 19 of the angle members 17. In this manner a passageway 63 is formed through the sheet 36 which communicates with the space 65 between the two sheets 35 and 36. The sheet 35 is formed with openings 64 in the same which also communicate with the space 65. These openings communicate with the exterior while the passageways 63 communicate with the interior of the conduit to which the frame 10 is attached. When the dampers are closed air flows from the exterior through the openings 64 along the space 65 and is discharged through the passageways 63 and into the interior of the structure to which the frame 10 is applied.

For the purpose of operating the dampers, arms 51 are secured to each of the shafts 29 and disposed on each side of the bearings 33. These arms have a pin 52 extending through the same. Extending between the pairs of arms 51 of the various dampers 28 are links 54. These links have attached to the upper ends of the same hubs 53 through which the pins 52 extend. Attached to the lower ends of the said links are clevises 55 which straddle the hubs 53 of adjoining links and through which the pins 52 also extend. The hubs 53 are rigidly secured to the links 54 while the clevises 55 are attached to said links by means of set screws 56. A set screw 70 screwed into each hub 53 holds the same attached to vthe corresponding pin 52. By means of the construction Cil described all of the arms are connected together and travel in unison.

The pin 52 of the lowermost arms 51 has pivotally mounted on it a connecting rod 57. This rod has a hub 53, the same as the links 54, through which the pin 52 passes. The connecting rod 57 has at its lower end a clevis 5S which straddles an arm 59 mounted on a shaft 60 driven by an electric motor 61. A pin 62 passes through said clevis and arm and pivotally connects the two together. Motor 61 is provided with a base which is attached to a bracket 67 by means of bolt 68. This bracket is in the form of a plate and overlies the flange 18 of angle member 17 of frame member 15. Bolts 69 secure said bracket to said frame member. Motor 61 is provided with reduction gearing, not shown, whereby the shaft 60 travels at a reduced rate of speed and the arm 59 moves only a fraction of a turn sufficient to raise and lower the connecting rod 57 an amount to swing the arms 51 and open and close the dampers 28.

The method of operation of the invention is obvious. When the dampers are closed the longitudinal portion 42 of one damper engages the longitudinal portion 46 of the adjacent damper, and the longitudinal portions of the upper and lower dampers engage the bars 50 to close the spaces 26 and 27. As these portions of the damper come in contact the said portions engage each other throughout the length of the same. This is accomplished by virtue of the fact that the sheets from which the damper is constructed can twist a small amount and such movement brings the surfaces into close engagement. Also the sheets may bend slightly to cause actual contact between all of the parts. In this way leakage to the opening in the frame is reduced and with only slight pressure between the parts. When the dampers are closed'air enters the openings 64 in the outer sheets 35, passes through the space 65 between said sheets and is discharged through the passageways 63 at the ends of sheets 36 and into the interior of the structure to which the damper is applied. This serves to maintain the damper cool and to circulate air through the same at all times.

The advantages of the invention are apparent. The device is extremely inexpensive to manufacture and can be built with existing tools and machinery. The damper never becomes overheated and a highly effective closure is procured. The sheets used in the formation of the damper are similar in construction so that equipment used for forming one sheet will form the other also. Assembly of the parts is simple. By the formation of the inner sheet shorter than the outer sheet and the openings in the outer sheet, air circulation through the damper is procured at no additional expense.

Changes in the specific form of the invention, as herein described, may be made within the scope of what is claimed without departing from the spirit of the invention.

Having described the invention, what is claimed as new and desired to be protected by Letters Patent is:

1. In combination a frame having an opening therein, a shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for rotational movement, a damper mounted on said shaft and comprising lirst and second sheets of flexible sheet material overlying one another and being disposed one on each side of said shaft, said first sheet having an edge longitudinal with respect to said shaft and having a marginal portion extending along said edge, the second sheet having a portion longitudinal with respect to said shaft extending along the marginal portion of said first sheet, said shaft being situated in spaced relation to said longitudinal edge, fastening means between said sheets and shaft and securing said sheets to said shaft, elongated closure means carried by said frame for engagement with the damper at the locality of said longitudinal edge, a channel on said second sheet disposed along the longitudinal portion thereof and having a groove facing said shaft, the marginal portion of the first sheet at the longitudinal edge thereof being disposed in s'aid groove and the edge of said marginal portion normally falling short of the bottom of said groove, said portion being slidable transversely in said groove and substantially in the plane thereof to permit of twisting and bending of the sheets to cause the damper to closely overlie said closure means throughout the extent thereof.

2. A damper comprising a shaft, rst and second sheets of flexible sheet material overlying one another and being disposed one on each side of said shaft, said first sheet having an edge longitudinal with respect to said shaft and having a marginal portionv extending along said edge, the second sheet having a portion longitudinal with respect to said shaft extending along the marginal portion of said first sheet, said shaft being situated in spaced relation to said longitudinal edge, fastening means between said sheets and shaft and securing said sheets to said shaft, a channel on said second sheet disposed along the longitudinal portion thereof and having a groove facing said shaft, the marginal portion of the first sheet at the longitudinal edge thereof being disposed in said groove and the edge of said marginal portion normally falling short of the bottom of said groove, said portion being slidable transversely in said groove and substantially in the plane thereof to permit of twisting and bending of the sheets.

3. In combination a frame having an opening therein, a shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for rotational movement, a damper mounted on said shaft and comprising first and second sheets of exible sheet material overlying one another and being disposed one on each side of said shaft, said first sheet having an edge, longitudinal with respect to said shaft and having a marginal portion extending along said edge, the second sheet having a portion longitudinal with respect to said shaft extending along the marginal portion of said first sheet, said shaft being situated in spaced relation to said longitudinal edge, fastening means between said sheets and shaft and securing said sheets to said shaft, a flange issuing from the longitudinal portion of said second sheet and doubled back upon the longitudinal portion of the Sheet from which it issues and being disposed in spaced relation thereto to form a channel therewith having a groove facing the shaft, the marginal portion of the iii-st sheet at the longitudinal edge thereof being disposed in said groove between the longitudinal portion of the second sheet and said flange and the edge of said marginal portion normally falling short of the bottom of said groove, said portion being slidable transversely in said groove and substantially in the plane thereof, a second shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for swinging movement, said shafts being substantially parallel, a second damper similar to said first damper and secured to said second shaft, said shafts being spaced apart a distance less than the sum of the distances from said shafts to said longitudinal edges, the outermost portions of said dampers engaging one another when the dampers are closed, the parts thereof twisting and bending to bring the dampers into contact with one another throughout the longitudinal extent thereof.

4. In combination a frame having an opening therein, a shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for rotational movement, a damper mounted on said shaft and comprising vfirst and second sheets of flexible sheet material overlying one another and being disposed one on each side of said shaft, said first sheet having an edge, longitudinal with respect to said shaft and having a marginal portion extending along said edge, the second sheet having a portion longitudinal with respect to said shaft extending along the marginal portion of said first sheet, said shaft being situated in spaced relation to said longitudinal edge, fastening means between said sheets and shaft and securing said sheets to said shaft, elongated closure means carried by said frame for engagement with the damper at the locality of said longitudinal edge, a flange issuing from the longitudinal portion of said second sheet and doubled back upon the longitudinal portion of the sheet from which it issues and being disposed in spaced relation thereto to form a channel therewith having a groove facing the shaft, the marginal portion of the first sheet at the longitudinal edge thereof being disposed in said groove between the longitudinal portion of the second sheet and said liange and the edge of said marginal portion normally falling short of the bottom of said groove, said portion being slidable transversely in said groove and substantially in the plane thereof to permit of twisting and bending of the sheets to cause the damper to closely overlie said closure means throughout the extent thereof.

5.` In combination a frame having an opening therein, a shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for rotational movement, a damper mounted on said shaft and comprising inner and outer sheets of flexible sheet material overlying one another and being disposed one on each side of said shaft, one of said sheets having an edge longitudinal with respect to said shaft spaced from the axis of said shaft, the other of said sheets having an edge following `along the denoted edge of said sheet, fastening means engageable with said sheets at the locality of said longitudinal edges and connecting said sheets together at said edge, other fastening means engageable with said shaft and sheets and securing the damper to said shaft, said sheets being spaced from each other intermediate said edges and shaft to form a space therebetween, said inner sheet being shorter than said outer sheet in a direction longitudinal of said shaft to form passageways at the ends of the damper communicating with the space between the sheets and with the ambient space on the inner side of the damper and said outer sheet having an opening therein and forming a passageway communicating with the space between the sheets and with the ambient space on the outer side of the damper, said passageways conducting air from the ambient space on the exterior of the damper and into the space between said sheets to cool said sheets and discharging it into the ambient space on the inner side of the damper.

6. A damper comprising a shaft, first and second sheets of flexible sheet material overlying one another and being disposed one on each side of said shaft, said first sheet having an edge longitudinal with respect to said shaft and having a marginal portion extending along said edge, the second sheet having a portion longitudinal with respect to said shaft extending along the marginal portion of said first sheet, said shaft being situated in spaced relation to said longitudinal edge, fastening means between said sheets and shaft and securing said sheets to said shaft, a flange issuing from the longitudinal portion of the second sheet and being disposed in spaced relation thereto to form a channel therewith having a groove facing the shaft, the marginal portion of the first sheet at the longitudinal edge thereof being disposed between the longitudinal portion of the second sheet and said ange and the edge of said marginal portion normally falling short of the bottom of said groove, said portion of the first sheet being slidable transversely in said groove to permit. of twisting and bending of the sheets at the locality of said marginal portions.

7. In combination a frame having an opening therein, a shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for rotational movement, a damper mounted on said shaft and comprising two sheets of exible material overlying one another and being disposed one on each side of said shaft fastening means between said sheets and shaft and securing said sheets to said shaft, one of said sheets having an edge longitudinal with respect to said shaft and having a marginal portion extending along said edge and disposed on one side of said shaft, one of said sheets having an edge longitudinal with respect to said shaft spaced from said iirst longitudinal edge and having a marginal portion extending along said edge and disposed on the other side of said shaft, said shaft being disposed intermediate said edges, certain of said sheets having longitudinal portions overlying said first named longitudinal portions, anges issuing therefrom and doubled back upon the same to form therewith channels with grooves facing the shaft, the other marginal portions being disposed in said grooves and the edges thereof normally falling short of the bottoms of said grooves and being slidable transversely in said grooves and substantially in the planes thereof to permit of twisting and bending of the sheets.

8. In combination, a frame having an opening therein, a shaft extending across said frame and opening, bearings carried by said frame and supporting said shaft for rotational movement, a damper mounted on said shaft and comprising two sheets of ilexible material overlying one another and straddling said shaft, fastening means between said sheets and shaft and securing said sheets to said shaft, each of said sheets having one terminal portion longitudinal with respect to said shaft and lying on one side of said shaft and also having another terminal portion longitudinal with respect to said shaft and lying on the other side of the shaft, one of said terminal portions on each side of the shaft being provided with a channel, said channels having grooves facing the shaft, the other terminal portions on each side of the shaft being disposed within the groove of the channel on the corresponding side of the shaft and having an edge longitudinal with respect to the shaft and normally falling short of the bottom of the groove, elongated closure means carried by said frame for engagement with the damper at the localities of said longitudinal edges, said last named terminal portions being slidable transversely in said grooves and substantially in the planes thereof to permit of twisting and bending of the sheets to cause the damper to closely overlie said closure means throughout the extent thereof.

References Cited in the le of this patent UNITED STATES PATENTS 160,496 Woodruff Mar. 2, 1875 1,542,989 Connery June 23, 1925 1,928,577 Tarone Sept. 26, 1933 1,994,365 Mathews Mar. 12, 1935 FOREIGN PATENTS 539,168 Great Britain Aug. 29, 1941 562,152 Great Britain June 20, 1944 

